class SalesStatistics {
  final DateTime date;
  final double totalRevenue;
  final int billCount;
  final Map<String, double> categoryRevenue;

  SalesStatistics({
    required this.date,
    required this.totalRevenue,
    required this.billCount,
    required this.categoryRevenue,
  });
}

class ProductSales {
  final String productName;
  final int totalQuantity;
  final double totalRevenue;
  final double averagePrice;

  ProductSales({
    required this.productName,
    required this.totalQuantity,
    required this.totalRevenue,
    required this.averagePrice,
  });
}